Position-measuring devices are widespread and are particularly used in machine tools for acquiring path information or angular information. These are often incremental position-measuring devices. To determine the relative position of two objects moving with respect to each other, they normally include an incremental scale graduation mark on the sides of a rule. This mark is scanned with the aid of a scanning unit, in order to generate incremental signals. Different scanning principles, e.g., optical or magnetic, are employed for this purpose.
On the basis of the scanning principle, the path information or angular information acquired by the scanning unit are usually provided in the form of sinusoidal current signals. Several position signals are often generated, which are out of phase with each other. If, for example, two position signals are present which are out of phase with each other by 90°, the direction of movement can be determined from the information as to which signal is leading or lagging. In the case of signals that are 180° out of phase, the susceptibility to interference may be reduced by generating a differential signal, since interference present on both signals is eliminated by subtraction. When a direct-current component is contained in the sinusoidal current signals, it is also compensated for by subtraction.
The following signal combinations are conventional:                four sinusoidal current signals, each having a 90° phase shift (0°; 90°; 180°, 270°), without a direct-current component        four sinusoidal current signals, each having a 90° phase shift (0°; 90°; 180°, 270°), with a direct-current component        three sinusoidal current signals, each having a 90° phase shift (0°; 90°; 180), with a direct-current component        three sinusoidal current signals, each having a 120° phase shift (0°; 120°; 240°), with a direct-current component        
Therefore, depending on the application case, there is a different number of sinusoidal current signals available, having different phase angles with respect to each other, the current signals being transmitted to a signal-processing device for analysis. There, the current signals are often initially converted to voltage signals in an input amplifier. In the case of signals that are 180° out of phase, a differential-voltage signal, which is proportional to the input signals, is often already formed in the input amplifier from the signals that are 180° out of phase. During the subsequent signal processing in the sequential electronics, inter alia, errors are corrected, and the period of the sinusoidal signals is subdivided by interpolation, and in this manner, the resolution of the position signals is increased. The position signals are subsequently converted into standardized formats and outputted.
In the course of progressive miniaturization, as well as for reasons of economic efficiency, it is becoming more and more common to integrate the electronic circuits, which are needed by incremental position-measuring devices to analyze the position signals, into application-specific chips (ASIC's). However, up to this point, the above-described plurality of measuring principles and the resulting type and number of signals to analyzed has made it necessary to develop a separate ASIC for each family of incremental position-measuring devices.
Disadvantages result from this: the cost of ASIC's only renders them economically interesting in large quantities, and their development and the associated product service is time-intensive and cost-intensive. Thus, there is a permanent need to design the electronic circuits for analyzing the position signals of incremental position-measuring devices that they may be used for several different applications. Therefore, when the electronic circuit is integrated into an ASIC, higher quantities are obtained, thereby increasing the economic efficiency and reducing the development expenditure.
For the sequential electronics for carrying out the above-described signal processing by error correction, interpolation, and conversion into standardized data formats, the same circuits may often already be used for several applications, when the input signals are appropriately processed in an input amplifier. Thus, the electronic circuits for analyzing position signals only differ in that the input amplifier is present.